Shiva Rastogi BNAL

As a nanotechnologies researcher, University of Idaho Coeur d’Alene’s Shiva Rastogi has many, very very tiny irons in the fire, each of them with the potential to have huge impacts in food and water safety, and medical diagnostics.

Rastogi is an nanomaterials and organic chemist, and an essential member of the University’s Biosensors and Nanotechnology Applications Laboratory (BNAL) research group in Coeur d’Alene.

“We are working on two major projects funded by a USDA special grant,” Rastogi explained. “The first one is to develop gold and silver nanoparticles for making a dry reagent test strip for toxins and food pathogens, like Escherichia coli (E. coli) and Salmonella species.”

“It’s like the pregnancy test stick, but we have some new ideas to increase the sensitivity and to make it work much better.”

In a related research effort, also funded by a USDA grant, Rastogi is developing magnetic nanoparticles and functionalizing them with proteins and DNA to capture, and identify, environmental E. coli.

Rastogi outlined the concept at the American Chemists Society’s national meeting and expo in San Francisco this spring, in a poster titled, “Capture and detection of natural populations of E. coli from freshwater using immune-magnetic nanoparticles.” The work was authored by Rastogi and University of Idaho scientists CharLene Gibson, David Newcombe and Larry Branen of the BNAL group working in Coeur d’Alene.

“We collect samples from local waters, and extract the E. coli,” Rastogi explained. “So we are synthesizing the magnetic nanoparticles and preparing them with specific antibodies and organic chemicals to enable them to capture these E. coli more effectively.”

BNAL researchers are using several techniques to detect the E. coli., including optical biosensing and fluorescent spectroscopy. The use of our fluorescent nanoparticles can enhance these detection systems.

Rastogi chose to work with silver and gold because they are very biocompatible materials that readily link any DNA or any protein. In turn, that DNA or protein works as a probe to catch the target protein or nucleic acid, providing quick identification of it. The technology has applications in food safety, providing detection of E. coli and other toxins, and in medical diagnostics for a wide range of disease detection.

This summer Rastogi will get help from Lake City High School Chemistry teacher Kevin Haler, investigating the use of gold and silver nanoparticles to improve the sensitivity and speed of pathogen detection. That research partnership will be funded over the next two summers by a $15,000 M.J. Murdock Grant.

“We are trying to reduce the time it takes to identify and quantify the bacteria,” Rastogi said. “Standard tests currently take 18-24 hours. We hope to bring the time it takes to identify a pathogen down to 2 or 3 hours.”

With the use of the magnetic particles, you can capture the organisms from a larger sample and get a more sensitive analysis and accurate reading, he added.

When the improvement is incorporated into biosensors, it will result in more rapid pathogen detection, ensuring freshness, and consumer safety. The biosensor will have direct application to perishable foods like spinach, peanut butter and meat, all of which have been sources of major E. coli outbreaks in the recent past.

The BNAL also works collaboratively with University of Idaho Professor Tom Bitterwolf to develop a zinc detection probe on modified silica nanoparticles and mesoporous silica particles. That BNAL team is synthesizing organic molecules that link to those particles—and only those—providing extremely accurate identification.

“Doctor Rastogi is an enthusiastic and highly skilled organic chemist. He has a strong confidence that he can synthesize required organic chemicals for use in our nanosensors, and has succeeded in developing a number of nanomaterials for our research,” said Larry Branen, University of Idaho Vice President for Northern Idaho and Director of BNAL. “Shiva is a strong team member and leader for our group.”

BNAL research focuses on applications of nanotechnology and biosensors to food, agricultural, environmental and health systems.

The University of Idaho Coeur d’Alene Science Lab, where Rastogi and other BNAL scientists work, is equipped for organic synthesis, nanomaterials synthesis, molecular biology, microbiology and food and water science research.